Top arms for textile fibre roller drafting mechanisms



March 10, 1970 J. M. NOVGUERA 3,499,191

TOP ARMS FOR TEXTILE FIBRE ROLLER DRAFTING MECHANISMS Filed Dec. 8, 19672 Sheets-Sheet 1 March 10,1970. J. M. NOGUERA 3,499,191

. TOP FOR TEXTILE FIBRE RQLLER DRAFTING MECHANISMS Filed 05;- a, 19s? 2Sheets-Sheet 2 United States Patent 3,499,191 TOP ARMS FOR TEXTILE FIBREROLLER DRAFTING MECHANISMS John Michael Noguera, London, England,assignor to Casablancas Limited, Salford, England, a British com- FiledDec. 8, 1967, Ser. No. 689,014 Int. Cl. D01h 5/50 US. Cl. 19--281 8Claims ABSTRACT OF THE DISCLOSURE A roller holding and weighting devicefor use with a top arm of a textile fibre roller drafting mechanism, thedevice comprising an outer holder part attachable to the top arm and aninner holder part mounted in the outer holder part for moving up anddown therein, against resilient pressure, guided by guide meansmaintaining parallelism between the axes of a top roller supported bythe inner holder part and the associated bottom roller but olferingsubstantially no frictional resistance to small up and down movements ofthe top roller and inner holder part.

This invention relates to top arms for textile fibre roller draftingmechanisms, the arms being of the type arranged to extend over thedrafting field from a rear mounting and having devices for holding andweighting consecutive dual-boss top rollers from their center necks.

In drafting systems employing such to arms, the top roller holding andweighting devices must fulfil a number of functions simultaneously. Inthe first place, each top roller must be held with its axis parallel toits associated bottom roller. Secondly, the working load on each toproller must be constant. To this end, the top roller must be permitted asmall amount of up and down movement in its holder, in order to allowboth for roller vibration as well as eccentricity, such movement beingas free as possible. Finally, such small movements which the top rollercarries out have to be confined to the plane containing the top rolleraxis and the associated bottom roller axis. Movement in any otherdirection will cause the nip between associated top and bottom rollersto move. Failure to meet any of the foregoing requirements willadversely aifect the quality of the roving or yarn being produced.

The known roller holding and weighting devices at present commonlyemployed with top arms fall broadly into two classes. In the firstclass, a roller holder is connected to a pivot located on the top arm atsome distance behind the working position of the holder, and a so-calledpendulum action tends to bring a supported top roller parallel with theassociated bottom roller. This arrangement however, has a number ofdrawbacks, one of which is that the centering force, which isautomatically generated if the top roller runs out of parallel with theassociated bottom roller, depends on the angle of misalignment andbecomes very small if the misalignment is small. Thus, while there is astrong tendency to correct serious deviation from parallelism, the smalldeviations which occur in practice are very slow to correct themselves,and the rollers tend to run slightly out of parallel for long periods oftime. A further drawback is that the position of the pivot is alwayssuch that the direction of the small up and down movements is not quitecorrect. There is so much mechanism directly behind the top roller axis,that the pivot has to be placed too high. The top roller must thereforemove forward as it .moves upwardly and the drafting nip moves with it.The weighting pressure may be applied by compression springs disposedbetween the holder and top arm and in front of the pivot axis.

In the second class, the roller holder has no pivot but does have apositive locating surface for the roller. Given accurate manufacture,parallelism is thus maintained correctly with this class of rollerholder and movement is always in the correct line. However, the rotationof the drafting rollers tends to urge the top roller forward in itsholder, making it bear against the locating surface. The pressure thuscaused provides frictional resistance to the small movements which, aspreviously stated, should be as free as possible.

A main object of the present invention is to provide a generallyimproved roller holding and weighting device which fulfils therequirements set forth and, at the same time, avoids the drawbacks anddisadvantages inherent in the aforesaid known arrangements.

Accordingly, the invention provides a roller holding and weightingdevice for use with a top arm of the kind specified; said deviceincluding an outer holder part attachable to the arm in a dependentposition, a separate dependent inner holder part which is adapted tostraddle and releasably grip the neck of a top roller, which innerholder part can freely move up and down in said outer part, a resilientpressure means operative to apply weighting pressure to the inner holderpart, and guide means consisting of .a guide surface and rider providedone on each said holder part at one end of said device and maintained inco-operation by said resilient pressure means; the arrangement beingsuch that in operation of the device with a top roller supported in theholder the guide means acts to maintain parallelism between the axes ofthe supported top roller and its associated bottom roller whilstoffering substantially no frictional resistance to small up and downmovements of the top roller and the inner holder part in the outerholder part, which latter movements are accommodated by a small rollingmovement of the rider against the guide surface, the end of the innerholder part that is at the end of the device remote from said guidemeans being capable of unhampered movement during such operation of thedevice.

For a better understanding of the present invention and to show how thesame may be carried into effect reference will now be made, by way ofexample, to the accompanying drawing, in which:

FIGURE 1 is a side view of a roller holding and weighting device,

FIGURE 2 is a sectional plan view of the roller holding and weightingdevice of FIGURE 1, taken on the line IIII of FIGURE 1,

FIGURE 3 is a front view of the roller holding and weighting device ofFIGURES 1 and 2, and

FIGURES 4 to 6 are views, similar to FIGURES 1 to 3 respectively, of analternative form of roller holding and weighting device.

In FIGURES l and 3 there is shown the free end of a top arm 1 of atextile fibre roller drafing mechanism having roller pairs arranged, forexample, in three consecu tive rows of upper and lower rollers, a dualboss top roller 2 of one upper row being shown in all the figures. Thetop arm 1, which may be of inverted channel section with a flattransverse top wall 3 and shallow dependent side walls 4, is pivoted andsupported in a convenient manner on a rear mounting (not shown) and,when operatively positioned, extends over the drafting field to overliethe center neck 5 of a dual-boss top roller 2 in each of the threeconsecutive rows. Catch means (also not shown) of any appropriateconstruction are also provided to hold the arm down in the aforesaidoperative position. To support and weight consecutive dual-boss toprollers 2, the arm 1 is further provided with a number of roller holdingand weighting devices of the invention, each composed of separate outerand inner roller holder parts 6, 7 and in an interposed resilientpressure device 8.

The outer holder part 6 of each such holding and weighting device is inthe form of a channel-member having side walls '9 which are partiallyclosed across the ends by walls 10 and joined by a generally flattransverse wall 11 that is the web of the channel-member, the side walls9 being extended in depth beyond the end walls 10' of thechannel-member. This channel-member is dimensioned to fit in an invertedposition between the top arm side walls 4, with the flat transverse wall11 secured against the undersurface of the arm top wall 3 by, forexample, bolt or screw means 12 (shown in FIGURE 1 but omitted fromFIGURE 3). Provision may also be made for adjustment of thechannel-member in the lengthwise direction of the arm 1 by providingelongated openings for the securing bolts or screws.

When the channel-member forming the outer holder part 6 is fitted to thearm 1 as aforesaid, the channel side walls 9 project downwardly belowthe arm side walls 4. Downwardly opening registering recesses 13 formedin the parts of the channel side walls 9 that extend below the end walls10- enable the side walls 9 to clear the center neck of the dual-bosstop roller 2 which is to be supported in the holder. Behind thedownwardly opening recesses 13, the rear portions of the parts of thechannel side walls 9 that extend below theend walls project downwardlysomewhat beyond the front portions of these parts of the side walls 9and are inter-connected by a cross-member 14. For a purpose explainedhereinafter, forwardly opening registering recesses 15 are provided inthe front edges of the channel side walls 9 clear of the channel endwalls 10.

The inner holder part 7 is in the form of a block which is dimensionedto fit loosely between the side walls 9 of the outer holder part 6 andto this end the block has a slightly tapered form from rear to front, asviewed in plan (FIGURE 2). This block is approximately the same lengthas the outer holder part 6 and is formed with a transverse downwardlyopening intermediate seating 16 for engaging around the center neck 5 ofa dual-boss top roller 2 to be supported by the holder. The block isalso provided with means, of any generally known type, for releasablyretaining the roller neck 2 within the seating 16. Near its forward end,the block is provided with small lateral pegs 17, one on each sidethereof, which project freely through the forwardly opening recesses 15in the front edges of the channel side walls 9 of the outer holder part6. These pegs 17 can abut the lower ends of the recesses 15 to limitdownward displacement of the forward end of the inner holder part 7 inrelation to the outer holder part 6. Downward displacement of the rearend of the inner holder part 7 is limited by abutment of the innerholder block against the cross-member 14 between said rear portions ofthe channel side walls 9, there being a groove 18 in the inner holderblock which receives the cross-member 14.

The resilient pressure device 8 for providing weighting pressure on adual-boss roller 2 engaged by the inner holder part 7 is in the form ofa pair of coil compression springs 19 which are inserted, one behind theother, between the inner and outer holder parts 7, 6. These springs 19are shown in FIGURE 1 but have been omitted from FIGURE 2. For thispurpose, upwardly directed spring locating recesses 20 are arranged toopen through the top of the inner holder block and correspondingdownwardly directed spring locating recesses 21 are provided in theundersurface of the transverse wall 11 of the upper holderchannel-member. The Spring locating recesses 21, 20 in the outer andinner holder parts 6, 7 are relatively positioned so that the upper endsof the coil springs 19 are set rearwardly to a small extent in relationto the lower spring ends. Thus, when under compression, a totalresultant force of the resilient pressure device that acts to applyweighting pressure to the inner holder part 7 is inclined with respectto the direction of up and down movement of the inner holder part 7 inthe outer holder part 6. Hence the springs 19 not only apply weightingpressure, but tend also slightly to urge the inner holder part 7 in aforward direction in relation to the outer holder part 6. Separation ofthe two holder parts 6, 7

- under the spring action is, however, limited as aforesaid.

To limit forward movement of the inner holder part 7 in relation to theouter holder part 6 under the spring influence, a pin 22 ofcircular-section extends through the inner holder block to project oneach side of the block. This pin 22 is located near the rear lowermostcorner of the block so that the pin axis will be substantially directlybehind the axis of a roll-er neck 5 when seated in the block. Theprojecting pin ends constitute a rider which bears against undercut rearedge portions 23 of said rear portions of the channel side walls 9 toprovide a defined guide path for movement of the inner holder part 7 inrelation to the outer holder part 6.

The roller holding and weighting device as described is, in use, raisedand lowered with the top arm 1 and, when not in the working position,the inner and outer parts 7, 6 of the holder are separated by theloading springs 19 as far as the limiting stops formed by the bar 14 andthe pegs 17 will allow. When the arm 1 is brought down into the workingposition, however, the contact of the top roller bosses with thecorresponding bottom rollers causes the loading springs 19 to becompressed and the inner holder part 7 to slide upwardly within theouter holder part 6. During this sliding movement, the relative locationof the inner and outer holder parts 7, 6 is at all times determined bythe line contact between the undercut rear edge portions 23 of said rearportions of the channel side walls 9 and the rider formed by the ends ofthe pin 22 projecting laterally from the inner holder block. Since thiscontact is permanent, despife the sliding movement, the parallelism ofthe rollers is thus always maintained. As a result, the inner and outerparts 7, 6 of the roller holder tend always to take up the correctworking position without any appreciable friction impeding theirrelative movement, which is opposed only by the desired resistance ofthe loading springs 19.

When the springs 19 are under compression the pegs 17 at the forward endof the inner holder part 7 move freely in the forwardly directedrecesses 15 in the channel side walls 9 of the outer holder part 6without contacting the recesses edges, once the pegs have moved awayfrom the bottom stopped position. The tapered form (FIGURE 2) of theinner holder 'block ensures that the possibility of contact between theinner and outer holder parts 7, 6 is minimized.

For purposes of assembly, the inner holder part 7 together with thecompression springs 19', the rear guide pin 22 being removed, areintroduced between the side walls 9 of the outer holder part 6 from thefront and are pushed backwards and upwards over the rear cross-member 14of the outer holder part 6 until the springs 19 are correctly located.The lateral pegs 17 at the front end of the inner holder part 7 are thenpositioned against the stops provided by the lower ends of the forwardlydirected recesses 15 in the outer holder part side walls 9. The rearguide pin 22 is then driven through the inner holder part 7 therebypreventing the assembly from becoming dismantled.

In the alternative form showing FIGS. 4 to 6, said rear portions of thechannel side walls 9 are not undercut but instead carry a pin 22'corresponding to the pin 22. In place of a bore to receive the pin 22the inner holder part 7 has a downwardly open s ot 24 in whi h the pincarried by said rear portions of the channel side walls 9 is located.The shank of this pin 22 constitutes a rider which bears against therear face of the slot just mentioned, which rear face provides a definedguide path for movement of the inner holder part 7 in relation to theouter holder part 6. As in the form shown in FIGS. 1 to 3, in thisalternative form during sliding movement of the inner holder part 7 inthe outer holder part 6, the relative location of the inner and outerholder parts 7, 6 is at all times determined by the line contact betweenthe rear face of the slot 24 and the rider formed by the shank of thepin 22 carried by said rear portions of the channel side walls 9.

In operation, any small up and down movements of a top roller supportedby either of the forms of holding and weighting devices as describedwill take place virtually freely, because a small rise and fall of theroller merely results in a small rolling movement of the rider on itsassociated guide path. No friction of any significance is involved, andthe line of contact between the rider and its associated guide path isalways directly behind the axis of the top roller. At the small anglesinvolved, therefore, the small movement will also always be made alongthe correct plane, i.e. that containing the two roller axes. Furthermorevery low frictional resistance is oifered to relatively large movementsof a top roller supported in either of the forms of holding andweighting device.

The inner and outer holder parts may be made of any material havingsuificient strength, mouldings of plastic material being especiallysuitable.

What is claimed is:

1. A roller holding and weighting device for use with a top arm of thekind specified; said device including an outer holder part attachable tothe arm in a dependent position, a separate dependent inner holder partfor straddling and releasably gripping the neck of a top roller, theinner holder part being mounted for freely moving up and down in saidouter part, a resilient pressure means for applying weighting pressureto the inner holder part, and guide means consisting of a guide surfaceand rider provided one on each said holder part at one end of saiddevice, said resilient pressure means acting on said holder parts andbeing inclined with respect to said guide surface to maintain said riderin line contact engagement with said guide surface, said guide surfacebeing operatively positioned such that with a top roller supported inthe inner holder part, the guide means acts to maintain parallelismbetween the axes of the supported top roller and its associated-bottomroller, said rider being rollable on said guide surface while oiferingsubstantially no frictional resistance to accommodate small up and downmovements of the top roller and the inner holder part in the outerholder part by permitting pivotal movement therebetween about saidrider, the end of the inner holder part that is at the end of the deviceremote from said guide means being capable of unhampered pivotalmovements during such operation of the device.

2. A roller holding and weighting device according to claim 1, whereinsaid outer holder part is a channel-member having side walls and isattachable to said arm in an inverted position, and wherein said innerholder part is a block dimensioned to fit loosely between the side wallsof the outer holder part, said inner holder part having a downwardlyopening seating for engaging the center neck of a dual-boss top rollerto be supported by the holder and the side walls of the outer holderpart being recessed to accommodate this center neck; said resilientpressure means being contained within the outer holder part by the innerholder part so as to act to urge the inner holder part downwardly out ofthe outer holder part, and stop means for retaining the inner holderpart in the outer holder part, said stop means being operative when noload is applied from below to a top roller supported by the device.

3. A roller holding and weighting device according to claim 2, whereinthe inner holder part has a tapering form that is narrowest at said endof the inner holder part that is at the end of the device remote fromsaid guide means.

4. A roller holding and weighting device according to claim 2, whereinsaid stop means includes, adjacent said end of said device remote fromsaid guide means, peg means carried by one of the parts for co-operationwith the other of the parts so as to be clear of the other of the partsduring said up and down movements of the inner holder part in the outerholder part and so as to engage the other of the parts when no load isapplied from below to a top roller supported by the device.

5. A roller holding and weighting device according to claim 2, whereinsaid stop means further includes, adjacent said guide means, a recess inone of said inner and outer holder parts in which is located a membercarried by the other of said inner and outer holder parts, this memberbeing clear of the holder part in which the last-mentioned recess isformed during said up and down movements of the inner holder part in theouter holder part, and engaging the holder part in which saidlastmentioned recess is formed when no load is applied from below to atop roller supported by the device.

6. A roller holding and weighting device according to claim 2, whereinsaid guide surface is formed by the edges of undercut edge portions ofsaid side walls of the outer holder part, and wherein said rider isformed by the projecting ends of a pin carried py the inner holder part.

7. A roller holding and weighting device according to claim 2, whereinsaid guide surface is formed by a face of a slot formed in the innerholder part, and wherein said rider is formed by the shank of a pincarried by the side walls of the outer holder part.

8. A roller holding and weighting device according to claim 2, whereinsaid resilient pressure means is a pair of compression springs the endsof which are located in recesses formed in opposing faces of the innerand outer holder parts, one spring being adjacent said one end of thedevice and the other spring being adjacent the other end of the device.

References Cited UNITED STATES PATENTS 2,947,038 8/1960 Pfenningsberg19281 XR 3,072,974 1/1963 Stahlecker et al. 19-281 DORSEY NEWTON,Primary Examiner

